/*
 * @Author: long-xinyu2 2192763423@qq.com
 * @Date: 2025-03-11 18:47:55
 * @LastEditors: long-xinyu2 2192763423@qq.com
 * @LastEditTime: 2025-05-16 11:49:46
 * @FilePath: \algorithm\algorithm-training\2025_3_11.cpp
 * @Description: 这是默认设置,请设置`customMade`, 打开koroFileHeader查看配置 进行设置: https://github.com/OBKoro1/koro1FileHeader/wiki/%E9%85%8D%E7%BD%AE
 */
#include<iostream>
#include<cstring>
#include<vector>
#include<map>
#include<cstdio>
#include<algorithm>
#include<string>
#include<string.h>
#include<queue>
#include<math.h>
#include<set>
#include<functional>
#include<bits/stdc++.h>
using namespace std;
using ull = unsigned long long;
#define int long long
//using i128 = __int128_t;
inline int inc(int x, int v, int mod) { x += v;return x >= mod ? x - mod : x; }//代替取模+
#define endl '\n'
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;

const int N = 2e3 + 10, M = 1e3 + 10;

inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9')
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
        x = x * 10 + ch - '0', ch = getchar();
    return x * f;
}
int e[M], ne[M], h[N], idx;
void add(int a,int b)
{
    e[idx] = b, ne[idx] = h[a], h[a] = idx ++;
}

int arr[N];

int f[N][N];

void solve(int root,int m)
{
    if(root != 0) for(int i = 1; i <= m; i ++) f[root][i] = arr[root];

    for(int i = h[root]; i != -1; i = ne[i])
    {
        int ej = e[i];
        solve(ej,m - 1);
        int op = 0;
        if(root == 0) op = 1;
        for(int j = m; j >= op; j --)
        {
            int cnt = 1;
            if(root == 0) cnt = 0;
            for(int k = 0; k <= j - cnt; k ++)
            {
                f[root][j] = max(f[root][j],f[root][j - k] + f[ej][k]);
            }
        }
    }
}

void solve()
{
    memset(h,-1,sizeof h);
    int n,m;
    cin >> n >> m;
    for(int i = 1; i <= n; i ++)
    {
        int fa,x;
        cin >> fa >> x;
        arr[i] = x;
        add(fa,i);
    }
    solve(0,m);
    cout << f[0][m] << endl;
}
signed main()
{
    // ios::sync_with_stdio(0);
    // cin.tie(0);
    int tt;
    // cin >> tt;
    // cin.get();
    tt = 1;
    while (tt--)
    {
        solve();
    }
}